<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    ul {
        display: flex; 
        list-style: none;
    }

    li {
        flex: auto; 
        background-color: pink;
        margin: 2em;
    }
  </style>
</head>
<body>
  <ul>
    <li>
        This is just some random text  to buttress the point being explained.
    Some more random text to buttress the point being explained.
    </li>

    <li>This is just a shorter random text.</li>
</ul>
</body>
</html>